Various types of pumps have been available for many, many years. One type of pump that has been in use is a rotary vane pump. A rotary vane pump uses moveable sealing elements, or vanes, in the form of rigid blades, rollers, slippers, shoes, buckets, and the like. The vanes are moved in a generally circular motion, in conjunction with movement radially inward and outward by cam surfaces to maintain a fluid seal in the pump housing, between the input and output ports of the pump, during operation of the pump.
In the past, there have been several rotary vane pumps disclosed in the prior art, including those disclosed in U.S. Pat. No. 4,011,033; 4,061,450; 4,019,840; and 4,073,608 to Christy for positive displacement vane-type rotary pumps, incorporated herein by reference. These prior art pumps have vane members which extend radially outwardly from and are connected to a rotor mechanism so that upon rotation of the rotor the vanes move a uniform distance through an arc to pump fluid in the pumping channel from the inlet port to the outlet port.
A disadvantage of these prior art devices is that they have not been the most efficient form of pump. In addition, such prior art pumps have been known to wear out and have components that break, and thus need replacement after a limited amount of use. Also such pumps are not efficient to manufacture.
Accordingly, it is an object of the present invention to provide a rotary vane pump which effectively increases the flow of fluid through the pump. It is yet another object of the present invention to provide a rotary vane pump which is durable and reliable in operation. Another object of the present invention is to provide a rotary vane pump which is efficient in its use, yet cost effective in its manufacture. This and other objects of the present invention will become apparent in the further description of the invention herein contained,